Broccoli and cauliflower both contain vitamin C. Your body needs vitamin C to maintain a range of tissues. Without sufficient vitamin C, you cannot produce the structural protein collagen, leading to a breakdown of your blood vessel, skin, tooth and bone tissue. A diet rich in vitamin C might also help reduce your risk of heart disease, according to the Linus Pauling Institute. Adult men and women require 90 and 75 milligrams of vitamin C, respectively. A 1-cup serving of chopped broccoli contains 81.2 milligrams of the vitamin, while an equivalent serving of cauliflower contains 51.6 milligrams.